Guide to Lime

All lime products sold at the Sustainable Building Resource Centre are produced locally in the southwest of England by Limebase Ltd. We work together with Limebase Ltd to provide you with specialist information.

The following information is only a guide. For detailed information on the mixing and application of lime please contact DCRS for a place on their one day Lime Course.

Introduction

Lime has been used for thousands of years. The ancient Egyptians, Greeks and Romans used lime for building. In Britain every mediaeval stone building was constructed using lime mortar as were buildings of the 17th and 18th century. Lime is the correct material for historic and traditional buildings and has many benefits.

There are two types of lime; hydraulic lime and lime putty (non-hydraulic). Lime putty is made from burnt limestone and will only harden when in contact with the air. Hydraulic lime is made in a similar way but has a clay content of 6-25%. This means that it will set when in contact with water.

Lime is used for new construction and conservation work. For new stonework and brickwork, hydraulic lime can fulfill the structural requirements that Portland cements once answered.

Lime putty

Lime putty is the basic ingredient used for making mortars, renders and plasters and limewash.

Lime putty and aggregates should be thoroughly mixed in large batches using the paddle or roller mixer. The proportion of lime putty to aggregate is usually 1:3, but this will depend on the aggregate type and what you are mixing. No water should to be added to the mix, the more you work lime the looser it becomes.

Lime putty is available from the Centre in 30 litre tubs.

Mortar

Hydraulic lime based mortars are usually used for new building work.

For stone repair work and repointing lime putty mortars are often used. If you do not want to mix these yourself a ready mixed mortar is available from the Centre in 25kg bags.

Plaster

Internal plasters are usually based on putty lime or feebly hydraulic lime. Hair is always added for work on laths and wattle, and sometimes for applications on walling. Traditionally internal plasters are given a fine finish and painted with limewash or distemper.

Lime wash

Lime wash is the lime equivalent of paint. In its pure form it is finely sieved lime putty diluted with water. Pigments can be added to produce the broad range of creams, buffs, pinks, yellows and reds which adorn so many traditional buildings.

You can make your own lime wash using putty and pigment bought from the Centre, or a full range of ready mixed and ready to use lime washes can be bought from our website.

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